WDPN32 PGTW 140300 SUBJ/PROGNOSTIC REASONING FOR TYPHOON 10W (HALONG) WARNING NR 29// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 140000Z5 TO 170000Z8 JUL 02. A. TYPHOON (TY) 10W (HALONG), LOCATED APPROXIMATELY 146 NM SOUTH-SOUTHEAST OF OKINAWA, HAS TRACKED NORTHWESTWARD AT 14 KNOTS DURING THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 132330Z2 VISIBLE AND ENHANCED INFRARED SATELLITE IMAGERY, AS WELL AS RADAR AND SYNOPTIC DATA. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 102 TO 115 KNOTS. SATELLITE IMAGERY DEPICTS A 31 NM RAGGED, CLOUD FILLED EYE. SURROUNDING CLOUD TOP TEMPERATURES HAVE WARMED 15 DEGREES CELSIUS IN THE LAST 6 SIX HOURS, WHILE THE CENTRAL TEMPERATURE HAS COOLED 8 DEGREES CELSIUS. B. THE SUBTROPICAL RIDGE LOCATED NORTHEAST OF TY 10W IS EXPECTED TO REMAIN QUASI-STATIONARY OVER THE FORECAST PERIOD. TY 10W IS EXPECTED TO TRACK NORTHWESTWARD FOR THE NEXT 12 HOURS TOWARDS A WEAKNESS IN THE SUBTROPICAL RIDGE LOCATED IN THE EAST CHINA SEA. THEN, TY 10W WILL BEGIN TRACKING NORTHWARD UNDER THE INFLUENCE OF THE MIDLATITUDE WESTERLIES ALONG THE NORTHERN PERIPHERY OF THE SUBTROPICAL RIDGE. THE AVAILABLE DYNAMIC AIDS CONSISTING OF THE NCEP AVIATION (AVN), NOGAPS, UKMET (EGRR), GFDN, COAMPS, AND JAPANESE GLOBAL (JGSM) AND TYPHOON (JTYM) MODELS ARE IN GOOD AGREEMENT WITH THIS SCENARIO IN TERMS OF TRACK DIRECTION AND VERY SLIGHTLY ON SPEED. EGRR TRACKS THE SYSTEM FASTEST WHILE THE JGSM IS THE SLOWEST. THIS APPEARS TO BE A FACTOR OF THE ORIENTATION OF THE RIDGE AND THE STRENGTH OF THE SYSTEM REPRESENTED IN THE MODELS. OUR FORECAST IS BASED ON A BLEND OF ALL AVAILABLE DYNAMIC AIDS. C. TY 10W IS EXPECTED TO CONTINUE TO WEAKEN AS IT TRACKS NORTHWESTWARD ALONG THE WESTERN EDGE OF THE SUBTROPICAL RIDGE TO THE NORTHEAST AS THE SYSTEM BEGINS TO BECOME EXTROPICAL AS IT INTERACTS WITH A SHORTWAVE TROUGH MOVING EASTWARD OVER CHINA. INTENSITY DECREASES WILL BECOME MORE RAPID AFTER THE EARLY PERIOD AS TY 10W TRACKS OVER INCREASINGLY COOLER WATERS, ENTRAINS COOLER AIR FROM THE NORTH, AND INTERACTS WITH THE LAND. D. CURRENT WIND RADII ARE BASED ON A RECENT QUICKSCAT PASS AND SYNOPTIC DATA. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE-SIZED SYSTEM. 3. FORECAST TEAM: MAZANY/KENDALL/WARREN/EDBERG/SCHAEFER// NNNN